Clinical practice guidelines have been defined as “systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances” (1). Many organizations are working diligently to develop guidelines, and a great deal has been written on the process of development, the attributes of an ideal guideline, and the need for evaluation of development processes.

A substantial body of literature focuses on the dissemination and impact of guidelines. Unfortunately, there are many questions about and very few answers as to the best ways of disseminating guidelines and assessing their effect on physician behavior (2). The article by Gifford and colleagues in this issue studies the impact of a well-designed intervention to improve neurologists' adherence to specialty society-endorsed guidelines (3).